Teletypewriter keyboard



June 28, 1955 o. MOSER TELETYPEWRITER KEYBOARD Filed April 17, 1953 United States Patent TELETYPEWRITER KEYBOARD Otto Moser, Bern, Switzerland Application April 17, 1953, Serial No. 349,383

Claims priority, application Germany February 3, 1952 7 Claims. (Cl. 178-17) My invention relates to teletypewriters in which the individual type keys of a keyboard assembly control selectively the various code-pulse control members of a startstop transmitter whose electric pulse contact issues the selected code-pulse combinations to a single communication channel.

It is among the objects of my invention to simplify the mechanical construction of such teletypewriters, to facilitate assembling and disassembling the machine, and to make the interior mechanisms more readily accessible for inspection or repair.

To achieve these improvements, and in accordance with a feature of my invention, I design the type-key levers of the keyboard assembly as identical parts and mount them by means of respective identical pivots in several parallel rows on a single supporting plate so that the entire keyboard assembly forms a unit separable and exchangeable as a whole from the rest of the machinery. I further provide between the start-stop transmitter assembly and the keyboard assembly an interlockable motion-transmitting mechanism which has a multiplicity of transmission members operatively connected with the respective pulse control members of the transmitter and in a loose or separable force-transmitting engagement with the respective type levers so as to transmit the pivotal movement of any one type-key lever to the pulse transmitter without interfering with the exchangeability of the keyboard assembly. The intermediate mechanism has an interlocking device operatively linked with all said key levers to permit actuating only one of said key levers at a time.

These and other features of my invention, set forth with particularity in the claims annexed hereto, will be apparent from the embodiment exemplified by the drawing and described in the following. In the drawing:

Fig. 1 shows a cross sectional view of a teletypewriter;

Fig. 2 shows a detail of the same machine in a plane indicated in Fig. 1 by the line llll; and

Fig. 3 is a partial view of another detail, the plane of illustration being indicated in Fig. 1 by the line III-III.

The illustrated teletypewriter has a rigid frame structure 0 covered by a housing 2. The keyboard assembly of the machine has a base plate 1 removably secured to the frame structure 0. Plate 1 carries a multiplicity of type keys 3, each having a lever 4 pivoted on plate 1 by means of a pivot pin 5. The keys are arranged in several parallel rows extending perpendicular to the illustration plate of Fig. 1. The levers 4 have angular shape and are all designed as identical parts. The upper arm 4a of each lever above plate 1 is directed forwardly, that is, toward the place of the operator. The other arm 4b of each lever 4 passes downwardly through a hole of plate 1 and carries on its extremity a counterpoise 6 for returning the key after each actuation.

The start-stop transmitter assembly of the machine for issuing the key-controlled code-pulse combinations is also mounted on the frame structure 0. The transmitter assembly has a set of pulse control members designed as cam discs 7 of which only one is visible in the ice illustration. Each cam disc 7 has a lateral groove 7a which is closed upon itself about the disc axis and has at one point of its periphery an entrance slot 7b extending radially to the periphery of the disc. All cam discs 7 are mounted on a common shaft 8 driven by a motor (not illustrated) to perform a single full revolution in response to the actuation of any one of the type keys. Each cam disc 7 cooperates with a feeler lever 9 pivotally mounted on a shaft 10. The feeler lever 9 has a dog pin 11 located opposite the entrance slot 7b of cam disc 7 in the normal position of the disc. As will be more fully explained below, the actuation of the correlated type key causes the feeler lever 9 to move clockwise about its pivot shaft 10 in opposition to a spring 12, thus placing the dog pin 11 through slot 7b into groove 7a. During the immediately following revolution of cam disc 7, the pin 11 is caught in the groove 7a and follows the wavy configuration of the groove during one full revolution. When the revolution is completed, the pin 11 is free to move out of the groove through the slot 7b into the illustrated normal position under the bias imposed on lever 9 by the spring 12. The cam configuration of the groove 7a in each of the respective control discs is in accordance with the particular pulse combination corresponding to the one actuated key. As a result, the feeler lever 9 oscillates about its pivot during the revolution of disc 7 and transmits its reciprocation to a transverse rod 15 which is common to all feeler levers 9. Rod 15 is mounted on an assembly of arms 13 and 14, pivoted at 13', which transmits its reciprocating movements to an electric pulse switch 16, thereby controlling the switch to issue a pulse combination to the communication channel.

An intermediate mechanism is provided for transmitting and interlocking the key movements relative to the feeler arms 9. This mechanism has for each row of keys a separate channel rail 17 firmly secured to the frame structure 0. Each rail 17 has a U-shaped cross section and upwardly directed limbs. The arms 4b of the key levers 4 for each row of keys project into the space between the two limbs of the channel rail so that the limbs limit the pivotal movements of each key lever. A number of rods 18, one for each key, extend transverse to the longitudinal direction of the channel rails 17. The rods 18 are slidably guided in openings of the rails 17 and also in an opening of an additional channel rail similar to rails 17. One end of each rod 18 abuts loosely against the correlated key lever while the other end is loosely engaged with the correlated feeler lever 9. When any one of the type keys 3 is being depresed, the pertaining rod 18 slides toward the feeler lever 9 and turns the feeler lever about shaft 10, thus placing the'dog pin 11 into the groove 7a of cam disc 7 in the manner described in the foregoing.

- After completion of one full revolution of cam disc 7,

the spring 12, biasing the feeler lever 9 to the illustrated original position, also causes the rod 18 to shift toward the key lever into the original position.

The drive for the pulse-controlling cam discs 7 is released by means of a plate 21 (Figs. 1, 2) which is pivotally movable about a shaft 19 and engageable by each of the rods 18. Plate 20 is connected by a link 21 with a lever 23 pivoted on a shaft 22. Lever 23 controls a slip clutch 24 interposed between the shaft 8 and the continuously running drive motor. As apparent from Fig. 2, the plate 20 has a comb-shaped contour along its lower edge so that it forms a number of recesses which straddle the respective rods 18. Each rod 18 carries a shoulder ring adjacent to plate 20 and of a diameter larger than the Width of the recesses in plate 20, so that the displacement of any one rod 18 by the correlated type key causes the plate 20 to turn about its pivot shaft 19, thus controlling the lever 23 to close the clutch 24 for one turn of revolution.

For interlocking the type keys the intermediate mechanism is further equipped with a group of interlock rods that extend parallel to the transmission rods 18. Each interlock rod for the type row closest to the pulse control levers 9 consists of only one part 26. For simplicity of manufacture, each other interlock rod is composed of one part 26 and another part 27, the parts 26 and 27 being aligned and in a loose abutting engagement with each other. All parts 26 are identical, while the parts 27 have different lengths corresponding to the different distances of the respective key rows from the parts 26. The rod parts 26 cooperate with a ball-type interlock device known as such for typewriters. The interlock device comprises an elongated cage 23 attached to the channel structure 25 and extending lengthwise thereof. The cage 28 contains a row of steel balls 29 whose play in the longitudinal direction of the cage is eliminated when any one of the rod parts 26 enters into the cage and passes between two balls of the row. The rod parts 26 for the upper row of keys and the rod parts 27 for the other key rows are biased by spring pressure to abut loosely against the downwardly directed arms 41') of the respective key levers 4. The bias is produced by springs 39 which are mounted on the respective rod part 26 and bear against a shoulder ring 260: of the rod part. The effect of the interlock means is to automatically block all other keys when one or" them is actuated. Besides, the interlocking means also prevent the simultaneous actuation of several keys.

As in known teletypewriters, the machine according to the invention is also equipped with special keys (not illustrated) for the selective blocking of groups of type keys. For instance, when depressing a number key, all letter keys are blocked; and when depressing a letter key, all other keys are blocked. The selective blocking means comprise a toothed slide plate 31 (Figs. 1, 3) which extends transverse to the rod portions 26 and is displaceable in its longitudinal direction. Plate 31 is slidably mounted on the channel structure 17 adjacent to the channel structure 25. For selectively blocking one of two available type groups of type keys, the plate 31 is shifted between two end positions by the above-mentioned special keys. This places the teeth 31a of slide plate 31 in front of respective shoulder rings 26b of those rod parts 26 that are to be blocked in the particular position of plate 31, thus preventing an actuation of the type keys correlated to the blocked rod parts 26.

In comparison with the known start-stop single-channel teletypewriters introductorily mentioned, the described machine according to the invention is distinct by having the keyboard mechanism designed as an independent structural unit which is removable from the rest of the machine without disturbance of the other mechanisms. This facilitates assembling the teletypewriter during its manufacture as well as any inspection and repair of the machine. The machine is also well suitable for series production by virtue of the fact that it is composed of several individual assemblies, each comprising a large number of identical machine parts.

It will be apparent to those skilled in the art that my invention permits of various medications in the design and appearance of the teletypwriter components without departing from the essence of the invention and within the scope of the claims annexed hereto.

I claim:

1. With a teletypewriter comprising a keyboard assembly and a start-stop transmitter assembly having movable code-pulse control members and a pulse contact operably connected with said members for issuing respective code pulse combinations under selective control by said keyboard assembly, the combination comprising, a baseplate, said keyboard assembly forming with said baseplate an exchangeable unit, said base plate having a multiplicity of identical type key levers pivotally mounted thereon in several parallel rows, and an intermediate mechanism having a multiplicity of movable transmission members operatively connected with said respective control members and loosely engageable with said respective type levers for transmitting pivotal movement of each type lever to one of said respective codepulse control members, and said mechanism having an interlocking device common to all said key levers to permit actuation of only one of said respective key levers at a time.

2. A teletypewritcr according to claim 1, wherein each of said key levers is of angular structure to provide upper and lower arm portions the upper arm portion of which is disposed above said plate and the lower arm portion of which extends downwardly through said plate, the end of said upper arm portion being directed toward the operators place and having a key top, said lower arm portion being laterally abutted by one of said transmission members of said intermediate mechanism.

3. in a teletypewriter according to claim 2, said intermediate mechanism having for each of said row of key levers a channel rail parallel to said row, said rail having a U-shaped cross section and upwardly directed limbs, said lower arm portions of said key levers projecting into the space between said limbs so that said limbs limit the pivotal movements of said key levers, and said transmission members being elongated and slidably mounted on said channel rails in a direction transverse to said rails, and springs connected with said respective transmission members to bias them toward said respective lower arms for maintaining said key levers in normal position.

4. A teletypewriter, comprising a keyboard assembly, a code-pulse transmitter assembly having movable codepulse control members and a pulse contact operably connected with said members for issuing respective code pulse combinations under selective control by said keyboard assembly, said keyboard assembly having several rows of pivotally movable type key levers, an intermediate mechanism for transmitting the lever movement to said transmitter, said mechanism having for each of said rows a channel rail parallel to said row, said rail having a U-shaped cross section and upwardly directed limbs, said type key levers of each row having respective arms projecting between said limbs so that said limbs limit the pivotal movements of said key levers, a number of longitudinally displaceable transmission rods extending transverse to said channel rails and being slidably mounted on said rails, each of said rods having one end in abutting engagement with one of said respective lever arms and having the other end in engagement with one of said respective code-pulse control members for transmitting the key-lever movements to said members, a

release control plate pivoted about an axis parallel to said rows and engageable by each of said transmission rods to perform pivotal movement when any one of said rods is being moved by actuation of the correlated key lever, and linking means connecting said plate with said code-pulse transmitter for releasing the start-stop transmitter operation in response to actuation of any one of said key levers.

5. A teletypewriter according to claim 4, comprising a number of interlock rods slidably mounted in said rails in parallel relation to said transmission rods and having one end in engagement with said respective key-lever arms, each of said interlock rods having a biasing spring urging said interlock rod toward said arm, an interlock device extending transverse to said interlock rods, said interlock rods having their respective other ends all engageable with said device for blocking all other type levers upon actuation of any one of them.

6. In a teletypewriter according to claim 5, said interlock rods comprising two aligned rod parts abutting against each other, the rod parts adjacent to said interlock device having all the same length, and the rod parts adjacent to said key-lever arms having different lengths in accordance with the diffen: it spacing of said key levers from said interlock device.

7. In a teletypewriter according to claim 6, said rod parts of the same length having respective shoulder rings, a slider movable between selective positions in a direction transverse to the axes of said respective rod parts, said slider having groups of projections, one of said respective groups being located in the path of a selected group of said shoulder rings, whereby a selective group of said key levers is blocked by said slider depending upon the position of said slider.

5 References Cited in the file of this patent UNITED STATES PATENTS 338,691 Baldridge Mar. 30, 1886 2,352,031 Steiner Aug. 8, 1941 

